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81.
A spectroradiometer was developed for use on the ground and aboard ship. The instrument separates global and diffuse solar radiation with a rotating shading band. Calibration results are compared with those of other sun photometers. The instrument was also mounted on a stabilized platform during an experimental trial aboard ship on the Tyrrhenian Sea. Results are comparable with those obtained by handheld sun photometer. 相似文献
82.
GM Roshchina EB Lishnevskaia IA Sizova VA Orlova IM Tereshin 《Canadian Metallurgical Quarterly》1980,25(11):850-854
The technique of accumulating preparation of the mucosa and "turned out sac" was used to show that levorin, a polyenic antibiotic in a concentration of 10(-6) M, lowered the transport rate and accumulation of glucose by the epithelial cells of the rat thin intestine under conditions of oxygenation. Suppression of the glucose transport in the first stages resulted in partial inhibition of the transmembrane transfer. It is suggested that levorin suppression of the glucose transport through the erythrocyte apical membrane in the thin intestine is associated with a decrease in the electrochemical gradient of Na+. 相似文献
83.
The kinetics of the male gametogenesis during the pregonadal period, prespermatogenesis, and "early" spermatogenesis has been described in detail. Concerning spermatogenesis in the adult individual reference is made to the articles of Courot, Hochereau-de Reviers and Ortavant (1970) and of Clermont (1972). The comparison of female and male gametogenesis (Fig. 1) shows that the "gonia stage" (asterisks) of the female germ cells is limited to one proliferation wave only, whereas the "gonia stage" of the male germ cells consists of a first proliferation wave, comparable to that of oogonia, a preparative phase to initiate spermatogenesis, and a second proliferation wave with renewal and differentiation of the spermatogonia. Germ cells in the "gonia stage" are highly sensitive towards ionising radiation and cytostatic drugs. 相似文献
84.
GM Shambes 《Canadian Metallurgical Quarterly》1976,55(5):221-252
The purpose of this study was to investigate "static" balance characteristics in four and eight year old children performing six developmental tasks leading to upright stance. The data were evaluated with electromyographic, center of gravity and photographic procedures. The results of the study indicated that the older age group of children demonstrated higher degrees of motor control in all the balance tasks involving upper and/or lower extremity support of the trunk. The eight year old children showed less postural sway, more definitive muscular localizations and smaller degrees of motor activity occurring during the execution of the developmental tasks. 相似文献
85.
Sheldon M. Wiederhorn Theo Fett Gabriele Rizzi Michael J. Hoffmann Jean-Pierre Guin 《Metallurgical and Materials Transactions A》2013,44(3):1164-1174
When a crack forms in silica glass, the surrounding environment flows into the crack opening, and water from the environment reacts with the glass to promote crack growth. A chemical reaction between water and the strained crack-tip bonds is commonly regarded as the cause of subcritical crack growth in glass. In silica glass, water can also have a secondary effect on crack growth. By penetrating into the glass, water generates a zone of swelling and, hence, creates a compression zone around the crack tip and on the newly formed fracture surfaces. This zone of compression acts as a fracture mechanics shield to the stresses at the crack tip, modifying both the strength and subcritical crack growth resistance of the glass. Water penetration is especially apparent in silica glass because of its low density and the fact that it contains no modifier ions. Using diffusion data from the literature, we show that the diffusion of water into silica glass can explain several significant experimental observations that have been reported on silica glass, including (1) the strengthening of silica glass by soaking the glass in water at elevated temperatures, (2) the observation of permanent crack face displacements near the crack tip of a silica specimen that had been soaked in water under load, and (3) the observation of high concentrations of water close to the fracture surfaces that had been formed in water. These effects are consistent with a model suggesting that crack growth in silica glass is modified by a physical swelling of the glass around the crack tip. An implication of water-induced swelling during fracture is that silica glass is more resistant to crack growth than it would be if swelling did not occur. 相似文献
86.
A method is proposed to be used as the first step in the ontology acquisition process. This method is based on the use of concept maps as a means of expression for the expert, followed by an application that assists the expert in detailing the structure of the knowledge represented in the map. This application analyses the concept map, taking into account the map topology and key words used by the expert. From this analysis a series of questions are presented to the expert that, when answered, reduce the map ambiguity and identify some common patterns in ontological representations, such as generalizations and mereologic relations. This information can be used by the knowledge engineer during further knowledge acquisition sessions or to direct the expert to a further improvement of the map. The method was tested by a group of volunteers, most of them engineers working at the aerospace sector, and the results suggest that both the use of concept mapping as well as the refining step are acceptable from the point of view of the end user, supporting the claim that this method is viable as an option to reduce some of the difficulties in large scale ontology construction. 相似文献
87.
88.
When Color Meets Computer Vision Color in Computer Vision: Fundamentals and Applications. By Theo Gevers,Arjan Gijsenij,Joost van de Weijer,Jan‐Mark Geusebroek,Hoboken, NJ: Wiley, 2012, Wiley-IS&T Series in Imaging Science and Technology,ISBN: 978‐0‐470‐89084‐4, 384 p
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A. Rizzi 《Color research and application》2014,39(4):412-423
89.
Vitamin E acetate addition to poly(d,l)lactic acid modifies its mechanical behavior without affecting biocompatibility
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Mechanical properties of poly(d,l )lactic acid films enriched with Vitamin E and Vitamin E Acetate (5–40% w/w) were investigated. The addition of both formulations resulted in increased polymer Young's modulus and tensile strength. Human foreskin fibroblasts and murine pre‐osteoblasts were used to assess the biocompatibility of polymers. Pre‐osteoblasts adhesion and proliferation were strongly decreased by Vitamin E, whereas Vitamin E Acetate did not alter cell proliferation. Collagen deposition was lower onto Vitamin E blended polymers than onto native and Vitamin E Acetate blended ones. Fibroblasts adhesion and proliferation were increased by both Vitamin E and Vitamin E Acetate addition. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39970. 相似文献
90.
Elena Bresciani Nicola Squillace Valentina Orsini Roberta Piolini Laura Rizzi Laura Molteni Ramona Meanti Alessandro Soria Giuseppe Lapadula Alessandra Bandera Andrea Gori Paolo Bonfanti Robert John Omeljaniuk Vittorio Locatelli Antonio Torsello 《International journal of molecular sciences》2022,23(7)
Combined AntiRetroviral Treatments (cARTs) used for HIV infection may result in varied metabolic complications, which in some cases, may be related to patient genetic factors, particularly microRNAs. The use of monozygotic twins, differing only for HIV infection, presents a unique and powerful model for the controlled analysis of potential alterations of miRNAs regulation consequent to cART treatment. Profiling of 2578 mature miRNA in the subcutaneous (SC) adipose tissue and plasma of monozygotic twins was investigated by the GeneChip® miRNA 4.1 array. Real-time PCR and ddPCR experiments were performed in order to validate differentially expressed miRNAs. Target genes of deregulated miRNAs were predicted by the miRDB database (prediction score > 70) and enrichment analysis was carried out with g:Profiler. Processes in SC adipose tissue most greatly affected by miRNA up-regulation included (i) macromolecular metabolic processes, (ii) regulation of neurogenesis, and (iii) protein phosphorylation. Furthermore, KEGG analysis revealed miRNA up-regulation involvement in (i) insulin signaling pathways, (ii) neurotrophin signaling pathways, and (iii) pancreatic cancer. By contrast, miRNA up-regulation in plasma was involved in (i) melanoma, (ii) p53 signaling pathways, and (iii) focal adhesion. Our findings suggest a mechanism that may increase the predisposition of HIV+ patients to insulin resistance and cancer. 相似文献